Venture capital gets the headlines, but the math tells a different story. Fewer than three percent of US startups are funded by VCs, angels, or banks combined. The other 97 percent grow using their customers' money, and many of them out-perform their venture-backed peers over the long haul. Dell, Microsoft, Zara, Costco, and Airbnb all did it. Here are the five customer-funded growth models every founder should know before they decide whether outside capital is actually the r